Ascale has a percent error of 5% the actual mass of a rock is 258g

this scale is likely to show the mass of either

245.1 253.0 256.7 257.5 g or 259.3 259.5 263.0 270.9 g.

, pick them wisely, you can pick one for each side. and remember it's not percent its percent error

245.1 g or 270.9 g

Step-by-step explanation:

Error in mass for the measurement is 5% of the actual mass . This simply means 5% of 258 grams. Mathematically,

error in mass = percentage error × actual mass

error in mass = 5 /100 × 258

error in mass = 1290/100

error in mass = 12.90 grams

Since the error in mass is 12.90 grams that means the scaled mass either has an increase of 12.9 g or decrease of 12.9 g from the actual mass.

scaled mass can be either 258 - 12.90 = 245.1 grams

or

258 + 12.90 = 270.9 grams

  5.   y=6; de=7; fg=8

  6.   x=4.2; jl=14.2; mn=13

step-by-step explanation:

when chords cross inside a circle, the product of the segment lengths is a constant.

5. dh×eh = fh×gh

  y = gh = dh×eh/fh = 3×4/2 . . . divide by the coefficient of gh

  y = 6

of course, the total chord length is the sum of the lengths of its segments.

  de = dh +eh = 3+4 = 7

  fg = fh +gh = 2+6 = 8

6. this problem works the same way as the previous one.

  x = lk = mk×nk/jk = 6×7/10 = 4.2

  jl = jk +lk = 10 +4.2 = 14.2

  mn = mk +nk = 6 +7 = 13

comment on chords and secants

you can think of the points h (problem 5) and k (problem 6) as points where the chords meet. a chord is part of a secant line, a line that intersects the circle in two points. one can also consider these points (h or k) to be the points where the respective secant lines meet.

then, the product that is a constant is the product of the distance from the meeting point (h or k) to one circle intersection with the distance from that meeting point to the other circle intersection. for problem 5, the constant is the product hd×he = hf×hg.

it turns out that this rule regarding the products of lengths to points of intersection is also true when the secants intersect outside the circle.

that is, you only need to remember one rule to work both kinds of problems.

x= 149. 24+7=31. 180-31=149

your welcome